Hopper



Patented Aug. 21, 1934 HOPPER Hervey'A.'Colvin, Saginaw, Mich.

Application October 5, 19-31, Serial No. 567,038 '3 Claims. (or. 221-118) -The structure to which this invention relates is a hopper operatively associated with power driven delivery mechanism that extracts the materialin a steady uniform manner. My improvement peritains tothe shape of the funnel that constitutes the lower part of the hopper, also to the location of the funnel discharge outlet relatively to the central axis of the hopper.

The object of the invention is to provide a .funnel that is free from the undesirable tendency inherent in the usual cone-shaped funnel, to arch, bridge or hang the material and consequently stop or impair the flow.

My improved funnel arrangement is capable of 1.5.;use with various known kinds of delivery or feedout mechanisms, hence the invention set forth in certain of the claims is not limited in that regard.

A preferred structure has been chosen for purposes of illustration and the invention will be .0 described accordingly.

A typical known hopper installation comprises a tank with a funnel-shaped spout, a power driven turn table being situated below the spout in oblique position on a vertical shaft. The table rotates 35 with a slow wabbling motion and so eases the material out through the continually changing annular space defined by the rim of the spout and the top of the turn table.

Installations of the kind described are well adapted for hoppers in dust collector systems that handle wood shavings, chips, sawdust and the refuse material from woodworking, leather working and other factories, but when associated with mechanical hopper discharging devices a serious ;fault in the funnel itself became apparent. Material would sometimes hang in the funnel even though the hopper delivery mechanism continued to work. The funnel was usually made symmetrical around a vertical axis, that is, it was either square, polygonal or circular in cross section, its central axis coinciding with the axis of the hopper, andhanging, bridging and sticking was found to be favored by the symmetrical cross section of the funnel.

I have discovered a simple, yet effective way to overcome this difficulty, solving an important problem in hopper operation and thus attaining the object of the invention.

In the drawing Fig. l is a side View, broken ;away, showing a tank embodying my improvement.

Fig. 2 shows the bottom of the funnel as viewed from below. 7

A tank 1 of any suitable form is provided into 5.1which material is delivered. Its lower part is a funnel 2. Below the rim 2a at the discharge end of the funnel is a rotary wabbling table 3 on ver-' tical shaft 4 that is driven by gears 5, reducing gears 6 and motor 7. Material from the tank gravitates down through the funnel and is easedv out through the undulating or variant annular opening 8 onto the table from which it is picked up by means of suction fan 9 and discharged to a collector, or elsewhere.

To apply my improvement to an installation of the kind described the central axis of the discharge end of the funnel is located in eccentric or offset relation to the central vertical axis of the top of the funnel where it joins the tank, and thereby is imparted to the funnel 2 an unsymmetrical cross sectional shape that varies along its length. The discharge end of the funnel is pref-' erably located so far off center that the central axis of the tank lies outside the boundary that defines the outer edge of the discharge outlet. The sides of the funnel preferably are made long enough to present a slope of not less than sixty degrees from the horizontal, that is, thirty degrees from the vertical on the under side of the funnel to give best results. This off-center arrangement of the discharge end of the funnel insures that hanging up will not occur in the material under ordinary conditions of plant operation. The material feeds down along the walls of the funnel steadily and at a substantially uniform rate onto the table. Arching, either in vertical planes or in horizontal planes Will not take place, under normal conditions of use, because the lack of symmetry in the shape of the funnel results in a perpetual condition of instability among the forces produced by the action of gravity within the material mass. A funnel that was symmetrical in shape about a vertical axis almost invariably brought about a condition of static balance in the mass, resulting in faulty delivery, whereas in my present invention that disadvantage is overcome.

Any other form of delivery mechanism might be employed instead of the wabbly turn table' herein illustrated, provided its resultant effect on 00 the material is substantially the same.

There is true co-operative relationship between the shape of the funnel and the feed-out mechanism, which will be apparent from the following considerations:

Assuming the hopper to be full, the weight of its contents is sustained partly by the downwardly convergent walls of the funnel and partly by the direct support afforded by the feed-out device that is located beneath the hopper outlet 10. In 119 discharge end 10 of the funnel the material naturally flows down more easily than it does around the edges. If the condition of the material as regards coarseness, moisture, weight etc; is just right, the relatively greater reluctance to downward flow along the walls of the funnel results in hanging or clogging. This tendency is found. to be greatest when the cross sectional shape of the funnel is symmetrical with relation to a vertical axis, and is least when unsymmetrical. attain the desirable lack of symmetry in the funnel by offsetting the outlet 10 with respect to the axis 31-1; of the top of the funnel. Tendency to clog is thereby eliminated and an even flow of material from the funnel is assured when the table 3 or other feed-out mechanism is put into operation.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In combination, a tank having a funnel shaped bottom portion that terminates in a discharge orifice positioned in eccentric relation to the vertical axis of the top of the funnel, a table spaced below the said orifice, and power actuated means associated with the table adapted to ease material outwardly from said orifice.

2. In combination, a tank having a funnel shaped bottom portion that terminates in a discharge orifice positioned in offset relation to the vertical axis of the upper part of the funnel, the

body of the funnel being of unsymmetrical cross sectional shape, and power actuated means adapted to remove material from said orifice, whereby hanging, bridging and arching of the material in the funnel is avoided.

'3. In combination, a tank having a funnelshaped bottom portion that terminates in a discharge orifice positioned in eccentric relation to the vertical axis of the funnel and power-actwlzted means to remove material from said orifice and to agitate vertically the contents of said tunnelshaped bottom portion. vHERIVEY ,A. GOLYIN. 

